Jack



Aug. 30, 1932. w RUNYAN I JACK Filed Jan. 14. 1929 [IVVENTOR A TTORNE YI made and assembled.

Patented Aug. 30, 1932 UNITED STATES GOMIANY, OF DAYTON, OHIO, ACORPORATION OF OHIO JACK Application filed January 14, 1929. Serial No.332,322.,

' lifting jack having a threaded lifting member which is yieldingly heldagainst rotational movements while it is moving upwardly or downwardlybut in which the restraining efi'ect upon'the lifting member isautomatically decreased at a limiting position of the latter;

Another object of the invention'is the provision of a double screwlifting jack which is simple in construction and easily and cheaplyOther objects and advantages of the invention will be apparent from thefollowing description and from the accompanying'drawing, in which y I VFig. 1 is a central vertical section of a double screw invention; I v

Fig. 2 is a vertical section through the jack standard on the line 2'-2of Fig. 1;

Fig. 3 is a vertical section through the jack standard on the line 3--3of Fig. 1;

Figs. 4. 5, 6 and 7 are sectional views of the jack at various pointscorresponding to the' line 4t4, 5-5, 6 6 and 77, respectively, of. Fig.2; Fig. 4 showing the position of the restraining spring when thelifting screw has reached its upper limit of travel, Figs. 5 and 6showing the lifting screw going upand down while positioned forresisting rotational movements, and Fig. 7 showing the screw'all the waydown and free to turn. 1

As illustrating a preferred embodiment the invention is shown asincorporated in a double screw jack such as is used for balloon tireswhich require extra lift, but of course the. invention may beincorporated 'in other adaptations thereof As shown, the jack comprisesa hollow standard 10, provided with a base 11. This standard ispreferably a metal casting of integral construction, the lower bodyporti on 12 of which is connected to the top portion 13 in an integralmanner by the connesting yoke portion 14.

Loosely mounted within the standard is a jack embodying the presenthollow sleeve-like outer lifting member 15. This lifting member isexternally threaded, and its outside diameter is such that it may PATENTOFFICE I 1 WILLIAM B. Bun an, or DAYTON, OHIO, AssI GNoR TO THE DAYTONMALLEABLE IRON freelypass through the circularbore 16 in y the upperportion of the jack and through the hollow passage 17 in the lowerportion.

In threaded engagement with the external 7 screw threads on this liftingmember is a collar or nut 18, this nut being held against endwisemovement by the upper portion 13 of thestandard. The lower side of'thisnut engages a suitable antifriction bearing or other thrust member 19which rests on top of the lowerportion of the standard. Rotationalmovements of the nut 18 may be effected by an actuating member 20rotatably mounted in the yoke 14., the inner end of this actuatingmember having suitable gear teeth 21 or the like engaging correspondingteeth 22 on the nut. The actuating mem ber 20 is preferably socketed at23 so that an actuating rod may be readily inserted in the socket forremote operation. The outer lifting member 15 is internally threaded at25 so that it telescopically receives the threaded inner lifting screw26. This inner screw, like the outer screw 15, is of about the sameheight as the total over-all height of the standard so that whenthe'various parts are extended the lift of the jack exceeds the heightof the standard. On'the top of the inner lifting screw 26 is fixed asuitable saddle 27 which is adapted to receive a load such as the'axleof an automobile.

It is desirable that meansbe provided whereby extension of the liftingmembers may had, when there i's no load on the jack. To this end meanstending to cause relative rotation between the outer screw and the nut,is incorporated in the structure.

Near the lower end of the lifting member 15,

the latter is circumferentially grooved at 29 to receive av springmember 30. This spring member preferably comprises a turn or two ofspring steel and takes the form ofa helical ring having an internaldiameter approximating the outside diameter of the groove 29. Anysuitable number of turns or fractional parts of turns of the wire may beemployed to give the desired degree ofrestraining effect of thisyielding member on the lifting member 15 to thus normally adequatelyrestrain the'lifting member against rotational movements, although thisrestraining is preferably so limited in degree that it may be overcomein case of binding of any of the other parts. As shown the helixcomprises a turn and a half so that the ends stick out in oppositedirections. The standard is interiorly provided along opposite sidesthereof with grooves 31 and 32 shown extending from top to bottom of thebody portion 12 of the standard. These grooves each receives one of thespring ends 33-or 34 toeprevent rotation of the spring and guide it forvertical movement. The width of the grooves is such throughout the mainpart of their lengths, that when one spring end engages a side of itsgroove the other spring end is about midway between its groove sides.

The spring 30 isso wound or wrapped about the outside of the outerlifting member 15 that when the latter is rotated it tends to cause thespring to rotate with it. However, when the end 34 for example of thisspring engages the abutment surface 35 of grooves 32 (see Fig. 5), thehelix member 30 then tends to wrap itself more tightly about the liftingmember 15 in gripping engagement therewith, and this will restrainrotational movements of the screw 15 in a. counterclockwise'direction.The result is that when the lifting member 15 is turned for example asshown in Fig; 5 in a counter-clockwise direction, and moving upwardly inthe standard, the end 34 of the spring moves up along the abutmentsurface 35 and normally holds the lifting member from rotating about itsown axis. When the lifting member is moved down into the standard,rotating clockwise as shown in Fig. 6, the end 33 of the spring helix 30presses against the abutment side 36 of the groove 31, and the spring isthus rendered operative, but in a reverse direction, and tends to wrapitself more tightly about the lifting member thus similarly'exerting aholding effect upon the latter. The effect of this restraining spring isto cause an axial or rectilinear movement of the outer lifting member 15without rotation, so that both lifting members move together axially outof the standardwhen the nut 18 is rotating. When the load is beinglowered and the nut 18 is rotated in the reverse direction, the twolifting screws are revegsely moved downwardly into the standar The upperend of the groove 32 is shaped as shown in Fig. 3, being offset at oneside as indicated at 37 so that after the end 34 of the spring rides upthe abutment surface 35 to the offset portion 37 of the groove, it maythen move over some little distance sufficient to enable the end 33 ofthe spring to engage the abutment surface 38 of the groove 31.

In other words when the spring reaches its upper limit of movement theabutment surface of the groove which has been causing the spring to grabor grip the lifting screw 15 is no longer engaged by the spring end andconsequently the surface of the groove which was effective while thespring was rising, no longer operates on the spring to render itoperative as a restraining means. The surface 38 of groove 31 is nowpressed by the opposite end of the spring and such action does not tendto cause the spring to grip the screw but on the contrary tends to causethe spring to be relieved of its pressure against the screw so that thescrew is permitted to turn without substantial restraint. A stop pin 40in the threads on the outside of the screw 15 engages the bottom of thenut 18when the screw 15 is elevated, so as to positively prevent anyfurther upward movement of the screw. Continued movement of the nut atthis time therefore turns the screw so that the inner screw 26, which isprevented from rotating about its own axis by reason of its engagementwith the load, thus screws up out of the lifting screw 15 to cause thefurther elevation of the load.

When the nut 18 rotates so as to cause a lowering of the load, thelifting member 15 tends to rotate clockwise as viewed in Fig. 4, andtherefore the spring end 33 is carried around to engage stop surface 36of groove 31 resulting in the imposition of restraint on screw 18normally preventing it from rotating about its own axis.

After the full retraction of the member 15 into the standard, should theload still be taken by the jack, the inner lifting screw 26 must beretracted and therefore the arrangement is such that the restraintagainst rotational movements of the outer lifting member 15 ismaterially lessened so that the latter may readily rotate with the nut,and screw the inner lifting member 26 down until the load is released.The lower end of the groove 31 is therefore offset like the upper end ofgroove 32 as indicated at 42. It will now be clear that when the end 33of the spring comes opposite the offset portion 42 it is carried arounda slight amount by the rotating screw 15 so that the opposite end 34 ofthe spring is moved into engagement with the abutment surface 43 of thegroove 32, this action immediately-relieving the spring from itstendency to grip the screw 15 so that the lattermay be rotated withoutmaterial restraint upon further rotational movement of the nut 18. Astop pin 44 near the upper end of screw 15 definitely limits thedownward movement of the screw when the end 33 of thespring is adjacentthe bottom of the groove in which it is mounted. Should the collar ornut 18 be turned so as to tend to raise the jack screws, when thelifting member 15 is at its lowermost position, the end made andassembled.

Patented Aug. 30, 1932 UNITED. STATES WILLIAM B. RUNYAN, or DAYTON,OHIO, ASSIGNOR To run DAYTON MALLEAMBLE IRON PATENT OFFI'CIE COMPANY, OFDAYTON, OHIO, A CORPORATION OF OHIO JACK Application ,filed January 14,1929. Serial 1T0. 332,322..

1 This invention relates to lifting jacks, and particularly to jacks ofthe multiple lifting type. V.

7 One object of the invention is to provide a I lifting jack having athreaded lifting member which is yieldingly held against rotationalmovements while it is moving upwardly or downwardly but in which therestraining effect upon the lifting member is automatically decreased ata limiting position latter.

Another object of the invention'is the provision of a double screwlifting jack which is simple in construction and easily and'cheaplyOther objects and advantages of the invention will be apparent from thefollowing description and from the accompanying drawing, in which- IFig. 1 is a central vertical section of a double screw jack embodyingthe present invention i Fig. 2 is a vertical section through the jackstandard on the line 22 of Fig. 1;

Fig. 3 is a vertical section through the jack standard on the line 3-3of Fig. 1;

Figs. 4. 5, 6 and 7 are, sectional views of the jack at various pointscorresponding to the line H. 55. 6-6 and 7.7, respectively, of Fig. 2;Fig. 4.- showing the position of the restraining spring when the liftingscrew has reached its upper limit of travel, Figs. 5 and 6 showing thelifting screw going up and down while positioned for resistingrotational movements, and Fig. 7 showing the screwall the way down andfree to turn.

As illustrating a preferred embodiment the invention is shown asincorporated in a double. screw jack such as'is used for balloon tires;which require extra lift, but'of course the. invention may beincorporated in other adaptations thereof. o As shown, the jackcomprises a hollow standard 10, provided with a base 11. This standardis preferably a metal casting of integral construction, the lower bodyporti on 12 of which is connected to the top portion 13 in an integralmanner bythe connecting yoke portion 14.

Loosely mounted within the standard is a of the hollowsleev'e like outerlifting member 15. Thislifting member-"is externally threaded, and itsoutside diameter is such that it may freely pass through thecircularbore 16 in the upper portion of the jack and through the hollowpassage 17 in the lower portion.

In threaded engagement with the external 7 screw threads on thisliftingmember is a collar or nut 18, this nut being held against endwisemovement'by the upper portion 13 of thestandard. The lower side of thisnut engages a suitable antifriction bearing or other thrust member 19which rests on top of the lowerportion of the standard. RO- V tationalmovements of the nut 18 may be effected by an actuating member 20rotatably mounted in'the yoke 14:,the inner end of this actuating memberhaving suitable gear teeth 21 or the like engaging correspond ing teeth22 on the nut. The actuating member 20 is preferably socketed at 23 sothat an actuating rod may be readily inserted in the socket for remoteoperation. The outer lifting member 15 is internally threaded at 25 sothat it telescopically receives the threaded inner lifting screw 26.This inner screw, like theouter screw 15, is of about the same height asthe total over-all height of the standard so that when thevarious partsare extended the lift of the jack exsaddle 27 which is adapted toreceive a load such as the'axle of an automobile.

It is desirable that means 7 be provided whereby extension of thelifting members may be had, when there'is no load on the jack. To thisend means tending to cause relative rotation between the outer screw andthe nut, is incorporated in the structure. Near the lower end of thelifting member 15, the latter is circumferentially grooved at 29 toreceive a spring member 30. This spring member preferably comprises aturn or two of spring steel and takes the form of a helical ring havingan internal diameter approximating the outside diameter of the groove29. Any suitable number of. turns or fractional parts of turns of thewire maybe employed to give the desired degree of restraining effect ofthis yielding member on the lifting member 15 to thus normallyadequately restrain the lifting member against rotational movements,although this restraining is preferably so limited in degree that it maybe overcome in case of binding of any of the other parts. As shown thehelix comprises a turn and a half so that the ends stick out in oppositedirections. The standard is interiorly provided along opposite sidesthereof with grooves 31 and 32 shown extending from top to bottom of thebody portion 12 of the standard. These grooves each receives one of thespring ends 33-or 34 tosprevent rotation of the spring and guide it forvertical movement. The ,width of the grooves is such throughout the mainpart of their lengths, that when one spring end engages a side ofitsgroove the other spring end is about midway between its groove sides.

The spring 30 is so wound or wrapped about the outside of the outerlifting member 15 that when the latter is rotated it tends to cause thespring to rotate with it. However, when the end 34 for example of thisspring engages the abutment surface 35 of grooves 32 (see Fig. 5), thehelix member 30 then tends to wrap itself more tightly about the liftingmember 15 in gripping engagement therewith, and this will restrainrotational movements of the screw 15 in a counterclockwise direction.The result is that when the lifting member 15 is turned for example asshown in Fig. 5 in a counter-clockwise direction, and moving upwardly inthe standard, the end 34 of the spring moves up along the abutmentsurface 35 and normally holds the lifting member from rotating about itsown axis. When the lifting memher is moved down into the standard.rotating clockwise as shown in Fig. 6, the end 33 of the spring helix 30presses against the abutment side 36 of the groove 31, and the spring isthus rendered operative, but in a reverse direction, and tends to wrapitself more tightly about the lifting member thus similarly exerting aholding effect upon the latter. The effect of this restraining spring isto cause an axial or rectilinear movement of-the outer lifting member 15without rotation, so that both lifting members move together axially outof the standard when the nut 18 is rotating. When the load is beinglowered and the nut 18 is rotated in the reverse direction, the twolifting screws are revegsely moved downwardly into the standar The upperend of the groove 32 is shaped as shown in Fig. 3, being offset at oneside as indicated at 37 so that after the end 34 of the spring rides upthe abutment surface 35 to the offset portion 37 of the groove, it maythen move over some little distance suflicient to enable the end 33 ofthe spring to engage the abutment surface 38'of the groove 31.

In other words when the spring reaches its upper limit of movement theabutment surface of the groove which has been causing the spring to grabor grip the lifting screw 15 is no longer engaged by the spring end andconsequently the surface of the groove which was effective while thespring was rising, no longer operates on the spring to render itoperative as a restraining means. The surface 38 of groove 31 is nowpressed by the opposite end of the spring and such action does not tendto cause the spring to grip the screw but on the contrary tends to causethe spring to be relieved of its pressure against the screw so that thescrew is permitted to turn without substantial restraint. A stop pin 40in the threads on the outside of the screw 15 engages the bottom of thenut l8'when the screw 15 is elevated, so as to positively prevent anyfurther upward movement of the screw. Continued movement of the nut atthis time therefore turns the screw so that the inner screw 26, which isprevented from rotating about its own axis by reason of its engagementwith the load, thus screws up out of the lifting screw 15 to cause thefurther elevation of the load.

When the nut 18 rotates so as to cause a lowering of the load, thelifting member 15 tends to rotate clockwise as viewed in Fig. 4, andtherefore the spring end 33 is carried around to engage stop surface 36of groove 31 resulting in the imposition of restraint on screw 18normally preventing it from rotating about its own axis.

After the full retraction of the member 15 into the standard, should theload still be taken by the jack, the inner lifting screw 26 must beretracted and therefore the arrangement is such that the restraintagainst rotational movements of the outer lifting member 15 ismaterially lessened so that the latter may readily rotate with the nut,and screw the inner lifting member 26 down until the load is released.The lower end of the groove 31 is therefore offset like the upper end ofgroove 32 as indicated at 42. It will now be.

clear that when the end 33 of the spring comes opposite the offsetportion 42 it is carried around a slight amount by the rotating screw 15so that the opposite end 34 of the spring is move'dinto engagement withthe abutment surface 43 of the groove 32, this action immediatelyrelieving the spring from its tendency to grip the screw 15 so that thelatter'may be rotated without material restraint upon further rotationalmovement of the nut 18. A stop pin 44 near the upper end of screw 15definitely limits the downward movement of the screw when the end 33 ofthe spring is adjacent the bottom of the groove in which it'is mounted.Should the collar or nut 18 be turned so as to tend to raise the ackscrews, when the lifting member 15 is at its lowermost position, the end33 of the spring 30 immediately is moved rotationally by the liftingscrew sufliciently far to cause the opposite end 3430f the spring topress against the abutmentsurface 35 of groove 32, causing the immediateyielding restraint of the liftingscrew 15 against any further rotationalmovements.

By reason of the construction just de scribed, the load may beeffectively raised, first by causing both liftingmembers to move axiallywith relation to the standard and without rotating on theirown axes.comparatively large outer liftingrnember therefore takes the heavyWeight of the load a during normal operation. When, however, excessivelyhigh lifts are required the smaller inner lifting member 26 becomeseffective,

the outer lifting member 15 being at the upper limit of its movementinthe standard under such conditions and rotating in the standard withoutsubstantial restraint; Relief of the restraining efli'ectwhich normallyprevents rotation of the outer lifting member when the latter is at itsupper or lower limiting position permits the jack to be more easilymanipulated and lessens the physical labor involved. The restraint uponthe outer lifting member 15, however, is at all times such that it maybe overcome by physical force to permit rotation of the outer liftingmember in the standard should other parts of the jack bind or for anyreason be prevented from operating properly.

While the form of apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that the inventionis not limited to this precise form of apparatus, and that changes maybe 7 members comprising an interiorly threaded rotatable collar engagingthe threads of the outer screw member, means yieldingly carried by theouter screw member for frictional rotation thereon and comprising a.

member slidably guided in the standard for restraining rotation. of andcausing axial movements of the outer screw member upon rotation of saidcollar, said standard having means for automatically varying saidrestraining effect for rendering said yielding,

member ineffective at a definite positioning of the outer screw member.

2. A lifting jack comprising a standard, an exteriorly threaded outerscrew member mounted in the standard, an inner screw memberthreaded 1nthe outer screw member, means for elevating said screw The hollowprising. a spring ring on the lower end: of

said outer screw member having an. end portion adapted for cooperationwith the stand-' ard to cause saidring to grip around the said screwvmember for. yieldingly resisting rotational movements of the said screwmember. I 3. A lifting jack comprising 'a hollow standard, an exteriorlythreaded outer screw member mounted in the.standard,an inner screwmemberthreaded in the outer screw member, means for elevatingv saidscrew members comprising an interiorly threaded rotatable collarengaging 'thethread's of the outer screw member, means yieldinglycarriedby the outer screw members and com-. prising a spring membercarried on the outside of said. outer screw member andhaving outwardlyprojecting. ends, said standard having means for restraining said springvmember against rotation within the standard and'being formed at theupper and lower limiting positions ofthe outer screw mem= ber to effectthe releaseof said spring from said outer screw member. a 1

-members comprising an interiorly threaded rotatable collar engaging thethreads of the "outer screw member, means yieldingly carried by theouter screw'member andcomprising a spring helix provided on'the outerscrew member and adapted to grip said outer screw member to resistrotational move: ments in either direction, and abutment means adaptedto engage'an end of said spring helix to prevent said spring fromgripping theouter screw member.

5. A. lifting jack comprising a frame, a liftingscrew in saidframe, acollar in threaded engagement with said lifting screw, means forrotatingsaid collar, and a spring member extending around said lifting screw,said standard having an abutment adapted to be'engaged by an end ofsaidspring member to cause the spring member to wrap itself aroundthelifting screw in gripping engagement therewith.

6. A'lifting jack comprising a frame, a lifting screw'in said frame, aninner lifting member in threaded engagement with said lifting screw,means for rotating said lifting screw, .a spring member engaging saidlifting screw and saidframe to yieldingly resist rotational movements ofsaid lifting screw, and means providing for automatic decrease ofthe-restraining effect of said spring at a limiting positionof the outerscrew member. 7; In a double screw lifting jack, outer

